1. Field of the Invention
The present invention relates to a liquid crystal display, and a photomask for manufacturing the same.
2. Discussion of the Related Art
Liquid crystal displays are a widely used flat panel display. A liquid crystal display has two display panels on which field generating electrodes, such as pixel electrodes and a common electrode, are formed, and a liquid crystal layer is interposed between the panels. In the liquid crystal display, voltages are applied to the field generating electrodes to generate an electric field over the liquid crystal layer, thereby determining the alignment of liquid crystal molecules of the liquid crystal layer. Accordingly, the polarization of incident light may be controlled, thereby performing image display.
The liquid crystal display further includes switching elements respectively connected to the pixel electrodes, and a plurality of signal lines, including gate and data lines for controlling the switching elements, to thereby apply voltages to the pixel electrodes.
Among the liquid crystal displays, a vertical alignment (VA) mode liquid crystal display, in which directors of liquid crystal molecules stand vertical to the upper and lower display panels when an electric field is not applied thereto, is highlighted in that it involves a high contrast ratio and a wide reference viewing angle. The reference viewing angle means a viewing angle with a contrast ratio of 1:10, or an inter-gray luminance inversion limitation angle.
With the VA mode liquid crystal display, a pixel may be bisected into two sub-pixels and different voltages are applied to the two sub-pixels, differentiating them in light transmittance, thereby making lateral visibility approximate to frontal visibility.
In order to differentiate the light transmittance, the same voltage may be applied to the two sub-pixels, and the voltage applied to either one of the two sub-pixels may be lowered using a separate switching element. However, in this case, the liquid crystal display may have many signal lines and contact holes, thereby deteriorating the aperture ratio.
Further, the liquid crystal display includes polarizers to intercept or pass light that is incident thereto. If the edge portion of the pixel electrode does not agree in direction to the polarization axis of the polarizers, leakage of light may occur at that edge of the pixel electrode.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.